1. Field of the Invention
The present invention relates to a webbing retractor which takes up a webbing for restraining a vehicle occupant by winding the webbing in layers onto a winding shaft.
2. Description of the Related Art
A webbing retractor, which winds up in layers a webbing for restraining a vehicle occupant, is attached to a vehicle body through a frame which, when viewed from top, is formed in a substantial U-shape. A winding shaft (spool) for taking up the webbing in layers is rotatably supported between a pair of leg plates of the frame. A spring cover made of resin is attached to the outer side of one of the leg plates. An urging means (a power spring), which applies an urging force to the winding shaft such that the shaft is rotated in the direction in which the webbing is taken up, is provided between the leg plate and the spring cover. Further, a sensor cover made of resin is attached to the outer side of the other leg plate. A locking mechanism (including a sensor) for instantaneously preventing the winding shaft from rotating in the direction in which the webbing is drawn out when the vehicle decelerates suddenly, is provided between the leg plate and the sensor cover.
In conventional webbing retractors, plugs are used as a means for fixing a sensor cover or the like to a leg plate of a frame. However, in the process of improving webbing retractors, the functions and forms of the sensor cover and the like have been changing, and fixing a cover by plugs may not always be adequate.